Kopano Groupware

Digital Sovereign Email & Calendaring Server

Kopano Groupware is an email and calendaring solution, which can be operated digitally sovereign. Its functionality is comparable to that of Microsoft Outlook and Exchange. Users can access their data via browser with the Kopano WebApp. Other clients can be connected via various interfaces.

Please note: The EOL of Kopano Groupware has been announced for 2025. Kopano Groupware is being succeeded by products and services based on Kopano Cloud. Please refer to this blog post for a quick overview.

Kopano Groupware

About Kopano Groupware

Kopano Groupware is an email and calendar server that provides users with their daily communication and organizational data on all devices and connects teams. Data can be jointly edited in public folders or shared with others from your own inbox.


  • Email, calendar, tasks, contacts, notes
  • WebApp, DeskApp, Mobile Devices & Standard Protocols
  • S/MIME, Basic-MDM, Files and other extensions


About Interoperability

Communication as a Service

In today’s as-a-Service world, things like email or calendars are part of the infrastructure. Regardless of the interface to the user, other services and applications must be able to access this data in a standardized and reliable way.

For Kopano Groupware we provide a RestAPI whose properties are based on Microsoft Graph. For the connection of other services, this means that the integration of one service already includes a large part of the connection to the other service. We see this interoperability and the resulting interchangeability as an important contribution to digital sovereignty.

Based on standard technology

Kopano Groupware is the only open source MAPI server worldwide. MAPI, the Messaging API, describes the data model that also underlies Microsoft’s e-mail and calendar services. It enables even complex multi-dimensionally linked elements such as invitations to recurring appointments with exceptions to be stored without errors.

Beyond the data storage, Kopano Groupware uses existing and proven Linux services.These are for example MTAs like Postfix, MariaBD/MySQL databases, Docker, Kubernetes, …

Frequently asked questions (FAQ)

Kopano Basic includes a minium of 10 users and Kopano Professional includes a minimum of 20 users in its base packages. For Kopano Enterprise it is 50 users. Our licenses for additional users increase by an increment of 5 users.
We used to offer Kopano Files as part of Kopano Basic and Kopano Files for Teams as commercial extension for Kopano Basic and part of Kopano Professional. Since a major rewrite of the Files Extension there is only one edition anymore, which is a commercial extension to Kopano Basic and included in Kopano Professional and higher.
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